1. Field of the Invention
This invention relates to an apparatus for needling a nonwoven web, comprising a brushlike endless web support, which is trained around reversing pulleys and consists of individual brush plates provided with tufts of web-supporting bristles arranged in rows of tufts which are continued on adjacent brush plates.
2. Description of the Prior Art
In order to avoid the disadvantages of stationary perforated or lamellar brush plates it is known (EP-B-183 952) to provide a traveling endless brushlike web support, which is trained around reversing pulleys and is composed of individual brush plates provided with bristle tufts arranged in longitudinal and transverse rows, which continuously extend throughout the length and width of the web support. To provide the bristles in a distribution which is as dense as possible over the web-supporting surface, said longitudinal and transverse rows of tufts are relatively offset so that the spacing of the mutually offset rows of tufts is decreased whereas a minimum spacing between adjacent tufts of bristles is ensured. But that decrease of the spacing of the rows of tufts involves difficulties at the joints between adjacent brush plates because with brush plates having straight edges the fact that the row spacing is smaller than the tuft spacing requires that the spacing of the marginal rows of tufts is larger than the row spacing on one brush plate. For this reason the brush plates mesh at their joints like meshing teeth and each bristle tuft of each marginal row of tufts is carried by a triangular tooth of the associated edge of the plate. In spite of that measure a uniform distribution of tufts on each brush plate cannot be provided at the joint between two brush plates and, as a result, the joints between the brush plates, which joints extend throughout the width and length of the web support, will be apparent in the surface pattern of the needled nonwoven web. In this connection it must be borne in mind that the bristle density will influence the resistance of the web support to the penetration of the needles and, as a result, will influence the formation of loops in the region in which the needle points emerge from the nonwoven web.